It has recently been announced that the mapping of the human genome has been completed. This historic development will lead to a myriad of developments ranging from the identification of the genetic basis of various diseases to the formulation and fabrication of new drugs and treatment protocols. All of this will only further serve to increase the already high demand for rapid information processing relating to polymer characterization, particularly that of various nucleic acids (i.e., DNA).
Heretofore, the sequencing of nucleic acids has been performed through chemical or enzymatic reactions. This allows for the nucleic acids to be separated into strains having differing lengths. This is generally tedious and laborious work and requires a significant amount of time and effort to complete. Thus, the results from any desired characterization of a particular polymer sequence are usually quite expensive and take a fair amount of time to obtain.
A significant advancement in the characterization of polymer molecules was introduced by Church et al. in U.S. Pat. No. 5,795,782 which issued on Aug. 18, 1998. Church et al. teach a method of causing polymer molecules, and in particular nucleic acids, to pass through an ion channel in an otherwise impermeable organic membrane. The membrane separates two pools of a conductive fluid solution containing a supply of the polymer material in question. By generating a voltage differential across the membrane, the polymer molecules can be ionized or polarized and guided through the ion channel. By measuring the various electrical characteristics of the membrane, the particular base of the polymer molecule can be identified by identifying the changes in these electrical characteristics as a particular base of the polymer molecule occludes the channel. Thus, each type of base member will exhibit unique characteristics that are identifiable by variations in monitored electrical parameters such as voltage or current.
The drawback of this device is that it is difficult to create an impermeable membrane having a sufficiently small ion channel that will allow the device to function properly. Church, et al. teaches using an organic membrane where an ion channel is created through the membrane via a chemical etching process. This is extremely difficult to do on a cost effective and repetitive scale. Specifically, the formation of an otherwise impermeable organic membrane and chemically etching or otherwise forming the ion channel is a hit or miss operation that may or may not actually produce the appropriately channeled membrane. Thus, while the concept of providing for the rapid determination of the character of polymer molecules is an extremely important one, no device has been provided that can be reliably produced while achieving accurate results.
Therefore, there exists a need to provide a high quality, reliable and easily reproducible polymer characterization device.